This application claims the benefit of Japanese Applications No. 2002-7773, No. 2002-7774, No. 2002-7775, filed in Japan on Jan. 16, 2002, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to the construction of a removable lens barrier device for protecting the front of a taking lens.
2. Description of the Related Art
A conventional lens cap for protecting a taking lens is capable of being removably attached to the front of the taking lens; in a condition in which a photograph is not being taken, this lens cap is attached to the front of the taking lens cylinder in order to protect the taking lens; when a photograph is being taken, this lens cap is removed, so that photography can be performed.
However, when a conventional lens cap as described above is removed, this lens cap must be stored and a location for storing this lens cap must be secured, so the use of a lens cap is troublesome and the possibility exists of the lens cap being lost after it has been removed.
Another type of conventional lens barrier device for lens protection arranged at the front of a taking lens comprises a barrier member that is capable of being rotated between a position that covers the front of the taking lens and an open position. When in the open position, this barrier member is held with being in contact with a stop member that is arranged in the vicinity of the axis of the aforementioned rotation.
However, with the conventional lens barrier device as described above, in the open condition of the barrier, there is a possibility of the barrier member accidentally coming into contact with an external obstacle. This leads to considerable stress being produced in the portions around the axis of rotation of the barrier member because the barrier member is in contact with the stop member, with the risk of damaging this, depending on the magnitude of the force of contact.
In view of the above, the present invention comprises a removable lens barrier device that protects the front of a taking lens, featuring the provision of a lens barrier device that is easy to use in that there is no need to detach the lens barrier device from the taking lens cylinder when a photograph is taken and further in which damage to the device can be prevented even if the barrier section accidentally comes into contact with some obstacle in the open condition or is subjected to wrong manual operation.
A lens barrier device according to one aspect of the present invention comprises a barrier movable between a position covering a front of a taking lens and a position withdrawn from the front of the taking lens, an engagement member capable of engagement with a filter screwthread of the taking lens in order to hold the barrier on the taking lens, and a rotary shaft that rotates the barrier section between the position covering the front of the taking lens and the position withdrawn from the front of the taking lens.
According to another aspect of the present invention, a lens barrier device comprises attaching means capable of removably attaching the lens barrier device to a filter screwthread of a taking lens, a barrier that is movable between a position covering the front of the taking lens and a position withdrawn from the front of the taking lens and attachment release means for releasing attachment of the lens barrier device to the filter screwhead by operation of the barrier when the barrier is moved beyond the position withdrawn from the covering position. Thus, the attached condition is released by the attachment release means by operation of the barrier.
Other features and benefits of the present invention will become apparent from the following description.